Drive for hydrofoil boat

ABSTRACT

A drive for a hydrofoil boat with two wings or foils mounted on the side of the boat and connected to flat vertical supports which are pivotably coupled to the port and starboard side of the boat. A pair of hydraulic drives are mounted to each of the vertical supports so that the supports can be pivoted on an axis parallel to the traveling direction of the boat and swiveled on a vertical axis in order to drive the boat and control its direction of travel.

United States Patent Eichler Dec. 16, 1975 DRIVE FOR HYDROFOIL BOAT 3,111,110 11/1963 Putten 115/31 [76] Inventor: Horst Eichler, Auf den Sande 12, I

5400 Koblenz, Germany Primary ExaminerTrygve M. Blix Assistant ExaminerSherman D. Basinger [22] Flled' 1974 Attorney, Agent, or FirmAllison C. Collard [21] App]. No.: 514,168

[57] ABSTRACT [30] Foreign Application Priority Data A d f h d f l b h f l O l 97 two or a y re 01 oat wit two wings or 015 ct l 3 Germany 2351034 mounted on the side of the boat and connected to flat 52 US. Cl. 11s 29- 114 66. 1+ 115 32 vertical Supports which are Piyotably COPPIed Int Clem 6 J port and starboard side of the boat. A pair of hydrau- [58] Field of l 28 30 3 lic drives are mounted to each of the vertical supports 14766 5 so that the supports can be pivoted on an axis parallel to the traveling direction of the boat and swiveled on {56] References Cited a vertical axis in order to drive the boat and control its UNITED STATES PATENTS drecnon of travel 396,672 1/1889 Stenard, Sr. /33 4 Claims, 3 Drawing Figures Tofal view 5Front Piston 2Universal Tainr US. Patent Dec. 16,1975 Sheetl0f2 3,926,138

56E E HG US. Patent Dec. 16,1975 Sheet20f2 3,926,138

Lateral Movement of the Wing Amglitude Outer Dead Point Inner Dead Point Midsnip Plane Cycle Lateral Movement Pivoting Pivoting of Support M I Zero Position Angle Pitch Outward! y Angle Pitch Inward/y Lateral Movement and Pivot S upp or t Midship Plane Travel Direction of Boat Fig.2

DRIVE FOR HYDROFOIL BOAT The subject invention relates to a drive for hydrofoil boats, whereby the supports for the foils are used as the drive in accordance with an agitating arm principle.

The known devices for hydrofoil boats consist of a completely immersed ship propeller, an air propeller, and a free jet. These devices have certain disadvantages with respect to the subject application. The drive by the ship propeller results in accelerating a small amount of water with a great loss of efficiency. The air propeller and the free jet are not economical for the achieveable speed of the boat.

All these known drives are subjected to a large relative energy loss due to turbulence, noise and heat loss. The free jet is similar in its operation to the drive of the subject application because of its increase in propulsion effectiveness during an increasing speed of the boat. In contrast to the drive by a ship propeller, the drive of the subject application applies a lesser acceleration to a large amount of water during an increasing speed of the boat. Thus, at an average speed, the acceleration of the water is smaller, the propulsion effectiveness of the drive is larger, and the noise level is lower.

It is an object of the invention to provide a drive for hydrofoil boats which have lower energy loss and in particular, have a lower noise level than conventional drives. This object of the invention is achieved by providing hydrofoil supports as drives which are laterally moveable with respect to the travelling direction of the boat. The supports engage a greater amount of water with their immersed segments during progressively increased speed, than a conventional ship propeller.

The inventive idea essentially consists of vertical sections which are moved as a drive, lateral with respect to the travelling direction of the boat, so that the laterial movements are complimented with a positive angle of pitch in the travelling direction of the boat. The structure of the inventive device is provided, preferably with vertical sections which on the one hand are pivoted around an axis parallel to the travelling direction of the boat by mechanical or hydraulical means, and on the other hand, are pivoted around a vertical axis. The vertical sections are thus preferably used as supports for the hydrofoils. The pivoting movements of the supports may be actuated with constant or variable amplitudes, laterally with respect to the travelling direction, and with a constant or variable angle of pitch of the vertical sections. The constant or variable forward and rearward travel of the boat may be actuated with a digital or analog control means.

Besides serving as a drive, the vertical sections may also be used as a control means. This is achieved by making the angles of pitch for the vertical sections at starboard and at port side of the boat unsymmetrical so that they can be pulled apart and retracted.

Other objects and features of the present invention will become apparent from the following detailed description when taken in connection with the accompanying drawings which disclose several embodiments of the invention. It is to be understood that the drawings are designed for the purposes of illustration only, and are not intended as a definition of the limits and scope of the invention disclosed.

In the drawings, wherein similar reference numerals denote similar elements throughout the several views:

FIG. 1A is a perspective view of the drive according to the invention;

FIG. 1B is a detail view of the movement mechanism;

and 1 FIG. 2 shows a schematic movement sketch of the drive.

As can be seen in FIGS. 1A and 1B, the drive essentially consists of vertical sections 1 which are moveably mounted on a boat 3 by means of universal joints 2. Vertical sections 1 are provided with rear hydraulic pistons 4 and front hydraulic pistons 5. A servo operated hydraulic system is provided in the boat. When rear hydraulic pistons 4 are pushed apart simultaneously with front pistons 5, sections 1 at the starboard and port sides move symmetrically away from the boat axis.

-When rear pistons 4 are more strongly pushed apart than front pistons 5, the rear edge of sections 1 move farther away from the boat axis at starboard and port side than the front edge. When pistons 4 and 5 are unsymmetrically pushed on the starboard side with respect to the pistons on port side, sections 1 at starboard and port side move unsymmetrically with respect to the travelling direction of the boat and act as a rudder, i.e., during an even drive of sections 1, an active rudder is obtained.

FIG. 2 shows the drive effect of sections 1 by movement sketches. The following discussion of function starts from the outermost dead center point, i.e., the largest expansion of the starboard sections away from the port side sections. Sections 1 are evenly expanded to the furthest position by pistons 4 and 5, and the angles of pitch of sections 1 in front are pointed at an outer angle in the travelling direction of the boat, since the front pistons 5 are expanded out further than rear piston 4. (See piston 6.) By expanding the rear pistons outwardly and retracting front pistons 5, the angle of pitch of sections 1 in front are positioned inwardly. (See position 7.)

By an unsymmetric retracting of pistons 4 and 5, profiles l are retracted to the smallest inner position by the dimension of the amplitude, i.e., to the inner dead center point. (See position 8.) By retracting rear pistons 4, and by expanding front pistons 5, the angles of pitch of sections 1 in front are expanded outwardly. (See position 9.)

The cycle is completed when, due to an even expansion of pistons 4 and 5, sections 1 return to their initial outermost expanded position allowed by the dimension of the amplitude, i.e., the outermost dead center point. (See position 10.)

While only a single embodiment of the present invention has been shown and described, it will be obvious to those of ordinary skill in the art that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention.

What is claimed is:

1. A drive for a hydrofoil boat comprising:

at least one foil substantially horizontally parallel to the longitudinal axis of the boat disposed on each side of the boat;

a flat vertical support member disposed substantially perpendicular to the longitudinal axis of said foils and having one end connected to each foil and its other end pivotably connected to the boat; and

drive means mounted on the boat and connected to each support member so that during a lateral movement to the starboard, the associated sup- 3 ports are pointed in an angular pitch toward the starboard, and when the supports are laterally moved toward the port side, the associated sections are pointed in an angular pitch toward the port side.

2. The drive according to claim 1 comprising:

universal joints means for mounting the said other ends of each of said supports on the boat so that said supports have two axes of freedom on the boat moving around a vertical axis and an axis parallel to the travelling direction of the boat.

3. The drive according to claim 2 comprising hydraulical means for pivoting the vertical supports around the vertical axis and the axis parallel to the travelling direction of the boat.

4. A drive for a hydrofoil boat comprising:

at least one foil disposed on each side of the boat, a

flat vertical support member having one end member connected to each foil and its other end pivotably connected to the boat, drive means mounted on the boat and connected to each support member so that during a lateral movement to the starboard, the associated supports are pointed in an angular pitch toward the starboard, and when the supports are laterally moved toward the port side, the associated sections are pointed in an angular pitch toward the port side, universal joints for mounting the ends of each of said supports on the boat so that said supports move around a vertical axis and an axis parallel to the travelling direction of the boat, hydraulic means for pivoting the vertical supports around the vertical axis and the axis parallel to the travelling direction of the boat, wherein:

by an unsymmetrical control of the hydraulic means,

the vertical supports at starboard are moved unsymmetrically toward the midship plane with respect to the supports at portside. 

1. A drive for a hydrofoil boat comprising: at least one foil substantially horizontally parallel to the longitudinal axis of the boat disposed on each side of the boat; a flat vertical support member disposed substantially perpendicular to the longitudinal axis of said foils and having one end connected to each foil and its other end pivotably connected to the boat; and drive means mounted on the boat and connected to each support member so that during a lateral movement to the starboard, the associated supports are pointed in an angular pitch toward the starboard, and when the supports are laterally moved toward the port side, the associated sections are pointed in an angular pitch toward the port side.
 2. The drive according to claim 1 comprising: universal joints means for mounting the said other ends of each of said supports oN the boat so that said supports have two axes of freedom on the boat moving around a vertical axis and an axis parallel to the travelling direction of the boat.
 3. The drive according to claim 2 comprising hydraulical means for pivoting the vertical supports around the vertical axis and the axis parallel to the travelling direction of the boat.
 4. A drive for a hydrofoil boat comprising: at least one foil disposed on each side of the boat, a flat vertical support member having one end member connected to each foil and its other end pivotably connected to the boat, drive means mounted on the boat and connected to each support member so that during a lateral movement to the starboard, the associated supports are pointed in an angular pitch toward the starboard, and when the supports are laterally moved toward the port side, the associated sections are pointed in an angular pitch toward the port side, universal joints for mounting the ends of each of said supports on the boat so that said supports move around a vertical axis and an axis parallel to the travelling direction of the boat, hydraulic means for pivoting the vertical supports around the vertical axis and the axis parallel to the travelling direction of the boat, wherein: by an unsymmetrical control of the hydraulic means, the vertical supports at starboard are moved unsymmetrically toward the midship plane with respect to the supports at portside. 